Plasma-assisted catalysis was used for the destruction of 500 ppm of dichloromethane, CH2Cl2 (DCM), in gas streams of air using a non-thermal, atmospheric pressure plasma utilising a dielectric packed bed. The combination of plasma and catalyst gave improved destruction of DCM. Eight catalysts which including alumina, TiO2 and various zeolites were investigated with the finding that alumina in a one-stage reactor configuration and TiO2 and HZSM-5 in two-stage configurations gave the best DCM destructions. The sodium zeolites are capable of reducing by 50% the unwanted NOx by-products, formed by plasma processing in air. The nature of the catalyst is important in terms of the destruction efficiency, end-product selectivity and NOx reduction. 相似文献
The learner translation corpus developed at the School of Translation and Interpreting of Pompeu Fabra University in Barcelona is a web-searchable resource created for pedagogical and research purposes. It comprises a multiple translation corpus (English–Catalan) featuring automatic linguistic annotation and manual error annotation, complemented with an interface for monolingual or bilingual querying of the data. The corpus can be used to identify common errors in the students’ work and to analyse their patterns of language use. It provides easy access to error samples and to multiple versions of the same source text sequence to be used as learning materials in various courses in the translator-training university curriculum. 相似文献
Depending on the calcium:phosphorus molar ratio of the initial precipitates determined by precipitation conditions (calcium:phosphorus molar ratio of reactants and pH of reaction environment), after sintering at 1250°C, monophase, biphase, or triphase ceramics consisting of hydroxyapatite, β-tricalcium phosphate, α-tricalcium phosphate, and calcium oxide were obtained. The phase composition and properties—i.e., density, shrinkage, hardness, bending strength, and roughness—of the fractured surfaces of the isostatically re-pressed sinters were determined. 相似文献
CoMo and NiMo supported Al2O3 catalysts have been investigated for hydrotreating of model molecule as well as industrial feedstock. Activity studies were carried out for thiophene and SRGO hydrodesulfurization (HDS) in an atmospheric pressure and batch reactor respectively. These activities on sulfided catalysts were evaluated as a function of promoter content [M/(M + Mo) = 0.30, 0.34, 0.39; M = Co or Ni] using fixed (ca. 8 wt.%) molybdenum content. The promoted catalysts were characterized by textural properties, XRD, and temperature programmed reduction (TPR). TPR spectra of the Co and Ni promoter catalysts showed that Ni promotes the easy reduction of Mo species compared with Co. With the variation of promoter content NiMo catalyst was found to be superior to CoMo catalyst for gas oil HDS, while at low-promoter content the opposite trend was observed for HDS of thiophene. The behavior was attributed to the several reaction mechanisms involved for gas oil HDS. A nice relationship was obtained for hydrodesulfurized gas oil refractive index (RI) and aromatic content, which corresponds to the Ni hydrogenation property. 相似文献
This work addresses the reduction of NOx by H2 under O2-rich conditions using Al2O3/SiO2-supported Pt catalysts with different loads of WOx promotor. The samples were thoroughly characterised by N2 physisorption, temperature-programmed desorption of CO, scanning electron microscopy, X-ray diffraction, laser raman spectroscopy, X-ray photoelectron spectroscopy and diffuse reflectance infrared fourier transform spectroscopy with probe molecule CO. The catalytic studies of the samples without WOx showed pronounced NOx conversion below 200 °C, whereas highest efficiency was related to small Pt particles. The introduction of WOx provided increasing deNOx activity as well as N2 selectivity. This promoting effect was referred to an additional reaction path at the Pt-WOx/Al2O3/SiO2 interface, whereas an electronic activation of Pt by strong metal support interaction was excluded.
Summary A melt-grafting approach was employed to prepare a novel functional polypropylene(FPP)—amino-terminated polyurethane grafted
polypropylene (PP-g-ATPU). The crystallization behaviors of PP and PP/FPP blends were characterized using differential scanning
calorimetry (DSC), wide angle X-ray scattering (WAXS) and polarized optical microscopy (POM). The effects of FPP composition
on crystallization behavior, crystal transformation, and morphology of PP/FPP crystalline were investigated. The results showed
that at a low dosage (<2.0 wt%) ATPU acted as a heterogeneous nucleation agent during the crystallization of PP/FPP blends.
However, when the content of ATPU reached 2.0 wt% or higher, ATPU deteriorated the crystallization of PP or PP/FPP blends.
The crystallite size decreased and the number of crystallites increased as the ATPU content increased. The Avrami analysis
was adopted to describe the isothermal crystallization process. The difference in the exponent n between PP and PP/FPP suggested that the isothermal crystallization kinetics of PP/FPP blends followed a three-dimensional
growth via heterogeneous nucleation. In terms of the half-time of the crystallization, t1/2, the crystallization rate of functional PP blends was faster than that of PP homopolymer at a given crystallization temperature. 相似文献
The evaluation of the microbiological charge present in Costa Rican samples as the evaluation of its antimicrobial activity over different microorganisms, including those associated to wound infections, will allow to emit criteria referred to its use in therapeutic treatments, specially as alternative therapy for cases involving antibiotic resistant bacteria. The microbiological charge of 25 honey samples, acquired in Costa Rican markets was evaluated through several indicators including total plate aerobic count, total plate anaerobic count, total aerobic spore count, total anaerobic spore count and molds and yeast count. Also, samples were inoculated in tubes with chopped meat media and plated in egg yolk agar in order to determine the presence of Clostridium botulinum. For the antimicrobial activity evaluation, the diffusion method in Muller Hinton agar was performed, testing different honey concentrations (100, 75, 50, 25, 12,5 and 6,25 % v/v) against Staphylococcus aureus (ATCC 25923), Staphylococcus epidermidis (UCR 2902), Pseudomonas aeruginosa (ATCC 9027), Escherichia coli (ATCC25922), Salmonella enteritidis (ATCC 13076), Listeria monocytogenes (ATCC 19116) and Aspergillus niger. The results obtained for the microbiological characterization of honey show that 91% of samples had counts equal or lower than 1,0 x 10(1) CFU/g. No positive result was obtained for the isolation of C. botulinum. 24 of the samples analyzed inhibited the growth of S. aureus even in a 25% v/v concentration, nevertheless, A. niger was no inhibited by any of the samples tested. 相似文献